Steam prime mover for marine propulsion.



C. G. CURTIS.

STEAM PRIME MOVER FOR MARINE PROPULSION.

APPLICATION FILED MAR.27, 1912,

1,078,838, Patented Nov. 18, 1913.

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O. G. CURTIS.

STEAM PRIME MOVER FOE MARINE PROPULSION.

APPLICATION FILED MAR. 27, 1912. I 1,978,838, Patented Nov.18, 1913.

5 SHEETSSHEET 2.

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G. G. CURTIS.

STEAM PRIME MOVER FOR MARINE PROPULSION.

APPLICATION FILED MAR. 27, 1912.

Patented N 0v. 18, 1913.

5 SHEETS-SHEET 3.

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G. G. CURTIS.

STEAM PRIME MOVER FOR MARINE PROPULSION.

APPLICATION FILED MAR.27, 1912. I 1,078,838. Q Patented Nov. 18, 1913.

5 SHEETS-SHEET 4.

Inventor A ttorneys.

C. G. CURTIS.

STEAM PRIME MOVER FOR MARINE PROPULSION. APPLICATION FILED MAR. 27, 1912.

1,078,838. Patented N0v.18,1 913.

If? 5 I E #7 i I I \\\\\\W 1 CHARLES G. CURTIS, OF NEW YORK, N. Y.

STEAM PRIME MOVER FOR MARINE PROPULSION.

Application filed March 27, 1912. Serial No. 686,510.

T 0 all whom it may concern:

Be it known that I, CHARLES Gr. CURTIS, a citizen ofthe United States, residing in the borough of Manhattan, city, county, and State of New York, have invented a certain new and useful Improvement in Steam Prime Movers for Marine Propulsion, of which the following is a specification.

The object I have in view is to produce an arrangement of steam turbines and speedreducing gearing for marine propulsion which will enable the development'and utilization of large powers, will operate efiiciently under cruising conditions, will be simple in construction and convenient in use.

In the accompanying drawing, Figure 1 is a plan view of the preferred arrangement; Fig. 2 is a longitudinal half section of one of the high pressure turbine elements; Fig. 3 is a longitudinal half section of one of the low pressure turbine elements; Fig. 4 is a plan view of a modified arrangement of the turbine elements and gearing; Fig. 5 is an end view of the arrangement shown in Fig.

. 4; Fig. 6 is a plan view of a further modification; and Figs. 7 and 8 are respectively side and end views. of the arrangement shown in Fig. 6.

i The live steam connections of the turbines and the steam connections between the turbine elements are omitted in, Figs. 4 and 6, but it will be understood that they are the same as in Fig. 1.

Referring particularly to Fig. 1: 9 is the propeller shaft, which may be one of two propeller shafts of a twin-screw arrange ment, and 10 represents the thrust collars upon this shaft. The propeller shaft is driven through speed-reducing gearing by two sets, A, B, of high and low pressure turbine elements connected with the propeller shaft by separate speed-reducing gears C, D. The turbine set A is composed of a high pressure go-ahead element 11 and a high pressure reverse element 12 preferably inclosed in the same casing, and of low pressure go-ahead and reverse elements 13, 14 inclosed in another casing. The shaft 15 of the high pressure elements, 11, 12, is connected by a slip coupling 16, with a divided pinion 17, of the herringbone type, wh ch pinion meshes with a divided gear-wheel 18 of the herringbone type, mounted on a short auxiliary shaft 19. lhe auxilia shaft 19 is in line with the propeller sha 9 and 1s coupled therewith by a coupling 20, which Specification of Letters Patent.

Patented Nov. is, 1913.

enables theturbine set A and its speed reduclng gear C to be uncoupled from the propeller shaft. The slip coupling 16 permits longitudinal movement of the pinion 17, so as to equalize the load and wear on the two sections of the pinion. Thrust collars 21, embraced by a thrust block (not shown) which may be included in the bearing of the turbine shaft, prevent excessive longitudinal movement of the turbine rotor. The lowpressure turbine elements 13, 14 are placed on he opposite side of the propeller shaft from the high pressure elements 11, 12. The shaft 22 of the low pressure elements is connected by a slip coupling 23, with a divided pinion 24, meshing with the divided gear wheel 18 on the opposite side from the pinion 17. The rotor of the low pressure elements may also be restrained from longitudinal movement by thrust collars 26. The turbine set B is composed of high pressure go-ahead and reverse elements 27, 28, preferably inclosed in a common casing, and of low pressure go-ahead and reverse elements 29, 30 likewise preferably inclosed in a common casing, the high and low pressure elements being located on opposite sides'of the propeller shaft, as in the case of the turbine elements of the set A 'and having their rotors connected in a similar way with the speed-reducinggear D, which is similar in all respects to the speed-reducing gear C. The divided gear-wheel of the speed-redud 'ing gear D, however, is mounted directly upon the propeller shaft 9. Live steam is supplied to the high pressure elements 11 and 27 by the steam pipe 31, controlled by the valve 32. Branch pipes 33, 34, controlled by separated valves 35, 36, lead from the pipe 31 to the inlets of the high pressure elements 11 and 27. The exhaust of the high pressure element 11 is connected by a pipe 37 with the inlet of the low pressure element 13. The exhaust of the high pressure element 27 is connected with the inlet of the low pressure element 29 by a pipe 38. Live steam is supplied to the reverse elements of the two sets by a pipe 39, controlled by a valve 40, from which branch pipes 41, 42, controlled by valves 43, 44, extend to the inlets of the high pressure reverse-elements 12 and 28. The exhausts of the high pressure reverse elements are connected with the inlets of the low pressure reverse elements by pipes 45, 46. The low pressure go-ahead and reverse elements of the two sets exhaust into the same spaces 47, 48, which are con:

- nected with the condensers (not shown),,as

will be understood. The high pressure element 27 of the turbine set B is provided with a number of cruising stages (as will be presently explained in connection with Fig. 2) which are cut out at high power by the opening of valved by-passes 49. Under high go-ahead turbine elements of the two sets will be controlled by the valve 32, and the steam will flow in parallel through the two turbine sets. Under cruising conditions, the turbine set A and gear C will be uncoupled from the propeller 1. shaft, which will be driven by the turbine set B and gear D, the by-passes 49 being closed to bring the cruising stages of the high pressure element 27 into operation. Likewise, at full power, the reversing elements of both sets will be simultaneously controlled by the valve 40, while under the cruising arrangement, the reverse element of set B will only be used. The provision for a parallel steam flow through both turbine sets at full power, and a single steam' flow through one turbine set at cruising power, gives a high efficiency under cruising conditions, which is enhanced by the employment of cruising stages in the high pressure element of the set B. The use of two turbine sets, each having a high and low pressure element, and each turbine element being connected with the shaft through its own pinion, produces such a sub-division of the power that a considerable power can be applied to a single propeller shaft, enough indeed to enable the arrangement to be used for the propulsion of battleships by the employment of twin-screws. The high and low pressure turbine elements of each set will be designed to develop approximately the same power so as to secure as nearly as practicable an equal division of the load on the pinions.

' In the arrangement as shown, the turbine set B will be employed at all times, and the turbine set A onlyunder conditions of high power. It is evident, however, that if, by reason of a break-down, it should become necessary to drive the propeller shaft by the turbine set A alone, the turbine elements of the set B can be'disconnected at the slip couplings between the rotor shafts and the pinions, and, if desired, the pinions themselves can be removed by taking off the bearingcaps and lifting the pinions from place.

The high pressure go-ahead and reverse elements of the turbine set B are illustrated in Fig. 2. The high pressure element 27 is composed of a number of impulse wheel stages, preferably velocity compounded, and separated by diaphragms, as usual in machines of this type, there being no pressure difference on the opposite sides of the r0- tating wheels, so that no longitudinal thrust is produced by the wheels.

Two of the.

wheel stages, 50 and 5.1, are cruising stages, which under high power conditions, are rendered inoperative by opening the by-passes 49, already referred to. Under cruising conditions, however, these by-passes are closed, and the cruising stages 50 and 51 are brought into operation. The high pressure reverse element 28, at the opposite end of the casing, is likewise an impulse-wheel velccity-compounded turbine, without pressure difference on opposite sides of the wheel. The high pressure turbines are, therefore, substantially internally balanced by their power producing elements, the small thrust block employed restraining the longitudinal movement of the rotor, which might be produced by thrusts arising from stepping the shaft and other minor causes. Since the exhaust from the go-ahead and reverse elements of the high pressure turbine must be separated for separate conveyance to the low pressure elements, a dia-.

phragm 52,- packed at the shaft, is provided for this purpose. The high pressure elements l1 and 12 of the turbine set A are precisely the same as the high pressure elements illustrated in Fig. 2, except that the cruising stages 50 and 51 and the by-passes 49 are omitted and the turbine made to this extent shorter.

In Fig. 3- the low pressure elements of either set are illustrated, these being alike for the two sets. The go-ahead low pressure element, which is shown to the right in Fig. 3, -consists of two reversed drum stages 53, 54, through which the steam flows in series, but in opposite directions, so that the thrust produced by the drum heads 55, 56 will be neutralized. This reverse drum construction is that described in my Patents Nos. 1,008,529, 1,008,530 and 1,008,531, and need not be further described here. By means of it, the turbine is internally balanced by its power producing elements. The low pressure reverse element, shown at the left of Fig. 3, consists of three impulse wheel stages velocity compounded, and having no material pressure differences on the opposite'sides of the wheels.

In the modified arangement shown in Fig. 4, the turbine sets A and B are grouped together, and the gears C, are grouped together. This requires the placing of the turbine elements of the two sets on different planes, ,as'illustrated in, Fig. 5; otherwise, the arrangement is the same as shown in Fig. 1. Theturbines of the set A drive the shaft through the gear C, and both the turbine elements of this set and the gear C may be uncoupled from the shaft by the coupling 20..,-The turbines of the set B drive the shaft throu h the gear D.

In the modi cation shown in Figs. 6, 7 and 8, the separate pinions of the four turbine elements mesh with the same divided their pinions gear-wheel, which is mounted upon the propeller shaft. This ,requires the turbines of one set to be placed on a higher plane than the turbines 0f the other set, as illustrated in Figs. 7 and 8. The turbine elements of the set A are arranged to be uncoupled from by means of the couplings 57, 58.

VVhat I claim is 1. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of a plurality of sets of high and low pressure steam turbine elements connected with. said shaft by speed-reducing gearing involving a separate pinion for each of the turbine elements, and steam connections producing a parallel steam flow through said turbine sets, substantially as set forth.

2. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of a plurality of sets of high and low pressure steam turbine elements connected with said shaft by speed-reducing gearing involving a separate pinion for each of the turbine elements,and means for uncoupling one or more of the turbine sets from the propeller shaft, substantially as set forth.

'3. In if'steam prime mover for marine propulsion, the combination with a propeller shaft, of two sets of high-and low pressure steam turbine elements connected with said shaft by speed-reducing gearing involving 4. In a steam prime mover for marinepropulsion, the combination with a propeller shaft, of a plurality of speed-reducing gears, each consisting of a gear wheel and a plurality of pinions, and a plurality of steam turbine elements connected with the separate pinions of each speed-reducing gear. substantially as set forth.

5. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of a plurality of sets of high and low pressure steam turbine elements, and separate speed-reducing gears connecting the turbine elements of each set with the shaft. involving a separate pinion for each turbine'element, substantially as set forth.

6. In a steam prime mover for marine propulsion, the combination with ,a propeller shaft, of two sets of high and low pressure steam turbine elements, speed reducing gearing connecting the turbine sets separately with'theshaft and means for uncoupling fromthe propeller shaft the turbines and speed-reducing gearing of one set, substantially as set forth.

7. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of two sets of high and low pressure steam turbine elements, steam connections producing a parallel steam flow through the two turbine sets, separate speedreducing gears connecting the two sets with the propeller shaft and means for uncoupling one of the turbine sets and its speedreducing gearing from the propeller shaft, substantially as set forth.

8.'In a steam prime mover for marine propulsion, the combination with a propeller shaft, of two sets of high and low pressure steam turbine elements, steam connections producing a parallel steam flow through the two turbine sets, separate speed-reducing gears connecting the elements of the two turbine sets with the propeller shaft, involving a separate pinion for each turbine element, and means for un coupling one turbine set and its speed reducing gearing from the propeller shaft, substantlally as set forth.

9. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of a set of high and low pres 'sure steam turbine elements, a speed-reducing gearing involving a separate pinion for each turbine element connecting the turbine set with an auxiliary shaft in line with the propeller shaft, means for coupling and uncoupling the auxiliary shaft with and from the propeller shaft, a second set of high and low pressure steam turbine elements and a speed-reducing gearing involving a separate pinion for each turbine element connecting the second turbine set directly with the propeller shaft, substantially as set forth. I

10. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of a plurality of sets of high and low pressure steam turbine elements connected with said shaft by speed-reducing gearing involving a separate pinion for each turbine element, the turbines being internally balanced by their power producing elements, substantially as set forth.

11. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of a plurality of sets of high and low pressuresteam turbine elements connected with said shaft by speed-reducing gearing involving a separate pinion for" propulsion, the com bine elements being internally balanced by means of reversed drum stages, substantially as set forth.

13. In a steam prime mover for marine propulsion, the combination with a propeller shaft, of a plurality of sets of high and low pressure steam turbine elements connected with said shaft by speed-reducing gearing involving a separate pinion for each turbine element, the high pressure turbine elements having impulse Wheel stages producing no axial thrust and the low pressure turbine elements having reversed drum stages, substantially as set forth. 7

14. In a steam rime mover for marine liination with a propeller shaft, of two sets of high and low pressure steam turbine elements connected with said shaft by speed-reducing gearing involving a separate pinion for each turbine element, steam connections producing a parallel a separate pinion for each turbine element,

steam connections producing a parallel steam flow through the two turbine sets, cruising stages in the lngh pressure element of one set and means for uncoupling the other turbine set from the propeller shaft, substantially as set forth.

This specification signed and witnessed this 23rd day of March, 1912.

' CHARLES G. CURTIS.

Witnesses: 1 JOHN L. LOTSCH, GUSTAV A. SCHELLACK.

"MAM" 

